Major histocompatibility complex class II-house dust mite peptide complex (MHC II-HDM complex)

Major histocompatibility complex (MHC) class II molecules on antigen-presenting cells (APCs) are essential for the initiation of the immune response against house dust mite (HDM) allergens. These heterodimeric surface glycoproteins, including HLA-DR, HLA-DQ, and HLA-DP, function by binding proteolytic fragments of HDM proteins, such as Der p 1 and Der p 2, and presenting them to CD4+ T helper cells (UniProt: P01903; PubMed: 26947171). In sensitized individuals, the recognition of these MHC II-HDM peptide complexes by T-cell receptors (TCRs) drives a Th2-polarized response, characterized by the secretion of cytokines like IL-4 and IL-13, which promote IgE production and allergic inflammation (StatPearls: MHC Class II). This complex is a primary target for allergen-specific immunotherapy, particularly peptide-based approaches like Synthetic Peptide Immuno-Regulatory Epitopes (SPIREs). These therapies aim to deliver specific HDM peptides that bind to MHC II molecules to induce T-cell anergy or regulatory T-cell (Treg) expansion, thereby modulating the underlying disease process in asthma and allergic rhinitis (Lancet: 378(9801):1475-1483). By targeting the MHC II-peptide interaction directly, these treatments seek to achieve desensitization with a reduced risk of IgE-mediated anaphylaxis compared to whole-allergen extracts.

Other names

HLA-DR-HDM complexMHC class II-house dust mite antigen complexMHC II-Der p peptide complexHLA-class II-HDM peptide complexMHC II-Der p 1 complexMHC II-Der p 2 complex

Induction of T-cell tolerance (anergy or deletion) or the induction of regulatory T cells (Tregs) through the presentation of specific allergenic epitopes to CD4+ T cells in the absence of costimulatory signals or in a tolerogenic context (PubMed: 21944032).